HEATER FOR OIL WELL AND HEATING CABLE FOR USE IN SAID HEATER Russian patent published in 2004 - IPC

FIELD: oil extractive industry.

SUBSTANCE: device has heating cable, adjuster and power source. Heating cable has three heating filaments protected by two thermo-isolation layers of blocks-polymer of propylene with ethylene and layer of winding of thermo-resistant fiber. Cable also has filling filaments made in form of isolated copper wires, placed along heating filaments. Diameters of filling filaments are selected to be such, that their outer surfaces are stopped against respective outer surfaces of heating filaments and inner surface of support for common cable armor. Above isolated heating and filling filaments a common winding is placed for armor and armor with forming of heating surfaces. Heating filaments in lower portion of cable are interconnected, and by other ends are connected to adjustable three-phase power source, control input of which is connected to output of adjuster. Filling filaments in lower portion of cable are also interconnected, and by upper ends are switched in shoulder of measurement bridge, measuring diagonal of which is connected to adjuster input.

EFFECT: higher durability, higher precision of temperature adjustment during operation.

2 cl, 4 dwg